“…However, reasonable forms of the coupling between the quantum subsystem and the classical spin bath cause such a basis to be complex (whereas, when the bath is described by canonical variables, the adiabatic basis is real in the absence of magnetic fields). Hence, an interesting prediction of the quantum-classical Liouville equation for spin baths is the a) sergi@ukzn.ac.za presence of open-path 41 geometric phases [42][43][44] in the evolution of the off-diagonal elements [45][46][47] of the density matrix. In order to introduce the formalism, one can consider a classical spin vector S whose energy is described by the Hamiltonian H SB (S), and denote its components with S I , I = x, y, z.…”